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I still don't know if I understood your question correctly, but here is how to use navigation & slam together for turtlebot 3 simulation:
Start the simulation as documented
export TURTLEBOT3_MODEL=waffle_pi roslaunch turtlebot3_gazebo turtlebot3_house.launch
Start SLAM with gmapping as [documented] (https://emanual.robotis.com/docs/en/p...): export TURTLEBOT3_MODEL=burger roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping
Start the navigation stack: The documentation says to launch turtlebot3_navigation.launch but this requires a map parameter for the map_server and amcl. But we already have the map from SLAM/gmapping, so we copy turtlebot3_navigation.launch and remove the lines for amcl and map_server:
turtlebot3_navigation_nomap.launch:
<launch>
<!-- Arguments -->
<arg name="model" default="$(env TURTLEBOT3_MODEL)" doc="model type [burger, waffle, waffle_pi]"/>
<arg name="open_rviz" default="true"/>
<arg name="move_forward_only" default="false"/>
<!-- Turtlebot3 -->
<include file="$(find turtlebot3_bringup)/launch/turtlebot3_remote.launch">
<arg name="model" value="$(arg model)" />
</include>
<!-- move_base -->
<include file="$(find turtlebot3_navigation)/launch/move_base.launch">
<arg name="model" value="$(arg model)" />
<arg name="move_forward_only" value="$(arg move_forward_only)"/>
</include>
<!-- rviz -->
<group if="$(arg open_rviz)">
<node pkg="rviz" type="rviz" name="rviz" required="true"
args="-d $(find turtlebot3_navigation)/rviz/turtlebot3_navigation.rviz"/>
</group>
</launch>
and launch it:
export TURTLEBOT3_MODEL=burger
roslaunch turtlebot3_navigation turtlebot3_navigation_nomap.launch
Finally we can start rviz and can now set a goal position for the navigation stack.
Below is my main launch file, it launches multiple nodes to convert sensors readings published from the simulation engine I am using.
<?xml version="1.0"?>
<launch>
<node pkg="ros_x_habitat" type="depth_ros.py" name="depth_ros" >
<remap from="depth" to="habitat/depth"/>
</node>
<node pkg="ros_x_habitat" type="rgb_ros.py" name="rgb_ros">
<remap from="rgb" to="habitat/rgb"/>
</node>
<node pkg="image_view" type="image_view" name="image_view">
<remap from="image" to="ros_img_rgb"/>
</node>
<node pkg="rqt_graph" type="rqt_graph" name="rqt_graph"/>
<node pkg="rqt_tf_tree" type="rqt_tf_tree" name="rqt_tf_tree"/>
<node pkg="depthimage_to_laserscan" type="depthimage_to_laserscan" name="depthimage_to_laserscan">
<remap from="image" to="ros_img_depth"/>
<remap from="camera_info" to="camera_info_topic"/>
<param name="output_frame_id" value="laser"/>
<param name="scan_time" value="0.025" />
</node>
<node pkg="laser_scan_matcher" type="laser_scan_matcher_node" name="laser_scan_matcher_node" output="screen">
<param name="max_iterations" value="10"/>
<param name="fixed_frame" value="odom"/>
<param name="base_frame" value="base_frame"/>
</node>
<node pkg="tf" type="static_transform_publisher" name="base_frame_to_laser" args="0.0 0.0 0.0 0.0 0.0 0.0 /base_frame /laser 50" />
</launch>
Here is the move_base launch file I am using, I guess we need to get rid of AMCL and map stuff since we don't want to use a map.
<?xml version="1.0"?>
<launch>
<arg name="map_path" default="$(find ros_x_habitat)/maps/mymap.yaml"/>
<master auto="start"/>
<!-- Run the map server -->
<node name="map_server" pkg="map_server" type="map_server" args="$(arg map_path)"/>
<!--- Run AMCL -->
<node pkg="amcl" type="amcl" name="amcl">
<!-- Publish scans from best pose at a max of 10 Hz -->
<param name="odom_model_type" value="diff"/>
<param name="odom_alpha5" value="0.2"/>
<param name="transform_tolerance" value="1" />
<param name="gui_publish_rate" value="10.0"/>
<param name="laser_max_beams" value="30"/>
<param name="min_particles" value="500"/>
<param name="max_particles" value="5000"/>
<param name="kld_err" value="0.05"/>
<param name="kld_z" value="0.99"/>
<param name="odom_alpha1" value="0.2"/>
<param name="odom_alpha2" value="0.2"/>
<!-- translation std dev, m -->
<param name="odom_alpha3" value="0.2"/>
<param name="odom_alpha4" value="0.2"/>
<param name="laser_z_hit" value="0.5"/>
<param name="laser_z_short" value="0.05"/>
<param name="laser_z_max" value="0.05"/>
<param name="laser_z_rand" value="0.5"/>
<param name="laser_sigma_hit" value="0.2"/>
<param name="laser_lambda_short" value="0.1"/>
<param name="laser_lambda_short" value="0.1"/>
<param name="laser_model_type" value="likelihood_field"/>
<!-- <param name="laser_model_type" value="beam"/> -->
<param name="laser_likelihood_max_dist" value="2.0"/>
<param name="update_min_d" value="0.2"/>
<param name="update_min_a" value="0.5"/>
<param name="odom_frame_id" value="odom"/>
<param name="resample_interval" value="1"/>
<param name="transform_tolerance" value="1"/>
<param name="recovery_alpha_slow" value="0.0"/>
<param name="recovery_alpha_fast" value="0.0"/>
<param name="base_frame_id " value="base_frame"/>
</node>
<node pkg="move_base ...It would have been a better style to edit your question and add the configuration there. Also a node graph please (Output of rqt_graph)
ok, then I recommend to use the turtlebot 3 simulation as example for this question, ok?
You can simply use a completely empty map and trick the system so that it believes you have provided a map. I did this in the past and it worked as expected, though I suggest you at least enable a local map so robots doesn't crash around.
What is the advantage of using an empty map over just not using the map frame?
If you don’t have a map frame, then in which global frame you are going to represent navigation goals ?
Let’s say you use Odom frame. That works too, in ros based navigation frameworks that I know, it’s common to have a global and local map, it’s easier just provide an empty map rather than playing with config files and figure a way to do navigation without a prior map. This is my personal opinion
Asked: 2021-07-22 02:00:42 -0500
Seen: 938 times
Last updated: Jul 27 '21
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You can configure the navigation stack global planner and global costmap to use odom instead of map as global frame, provided you have a painted floor plan. You could also use depthimage_to_laserscan for SLAM so you get a map. Or you can use rtabmap for SLAM.
can you please give me an example launch file of how to set this up? is there a similar turtle launch file I can refer to? I am so far not very sure about how each component should work with each other
Which version? 1) odom as global 2) depthimage_to_laserscan or 3) rtabmap?
I am on ROS noetic.
I meant: Which version do you want the example launch file for?
Oh I'd like to see an example of using odom as global so that I can run SLAM while planning.
Aah sorry, I misunderstood your question, so you are already creating the map with SLAM (e.g. gmapping) and have an area with unknown obstacles but still have a x/y coordinate for your robot to go to, is that correct? If not please rewrite your original question and add more details, e.g. node tree, launch files etc.
The global_planner has a parameter allow_unknown which might resolve your problem. But I have never used that it and have no experience with it.
You didn't misunderstand my question, I am not creating a map at all. All I want is to provide my robot with an RGB-D camera & a given goal location & its location relative to the goal. I want to let it navigate through an unknown space. So in short, using a SLAM package or not, I am not gonna create a map for the robot to use. I just need a ROS planner or a way to make this work.